We are testing two new reverse geocoding webservices.
The ‘find nearest address‘ web service finds the nearest street for a given point, determines whether the point is on the left or the right side of the street and interpolates the street number. The service then returns street name, street number, distance between the given point and the nearest point on the street in kilometres, county and state.
The ‘find nearest intersection‘ web service finds the nearest street for a given point, then it finds the nearest intersection of this street. It returns the nearest street, the street intersecting with this street at the next intersection, the distance between intersection and the given point in kilometres, county and state.
Both web services are using the so called ‘Tiger Line’ data set from the US census and are only available in the US. The quality and accuracy of the dataset can be visualized on a google maps tiger line mashup. Click on the map to see the closest street segments with street number on the left and right hand side of the segments. A further click on the street name will display the segment as a maps overlay:
GeoNames Blog 